ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
Thirty male rats (Sprague-Dawley), 25 days of age, were placed in exercise cages for seven days. They were matched into trios on the basis of the last four days total exercise and randomly placed in three groups: sedentary, spontaneous exercise and forced exercise. For the next 35 days, the sedentary group was permitted no exercise other than that allowed by their small individual cages. The spontaneous group remained in activity cages while the forced group in addition to being in activity cages, swam one 30-minute period each day with weights equal to 20% of the body weight attached to their tails. At the end of the 35-day activity period, the animals were sacrificed. The hind limbs were injected with India ink, embedded in gelatin and cut on the freezing microtome. The cross-sectional area of red and white fibers from the gastrocnemius muscles were measured by using the polar planimeter. Ink-filled capillaries were counted, in conjuction with fiber measurements.With forced and voluntary exercise programs there was a greater increase in crosssectional area of the red than of the white fibers. Under the same conditions, the increase in the number of capillaries per fiber was greater for white than for red fibers.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1091590106
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